Structural steelwork maker Severfield-Rowen warned yesterday that its full-year profit might be lower than market estimates as it expects cost overruns on two projects in the UK, sending its shares down 17 per cent. The company, which has worked on access bridges at Arsenal's Emirates Stadium, said last month it anticipated full-year results to show a marginal improvement over 2011. The company expects cost overruns of £1.6m and first-half pre-tax profit of £1.5m. The company expects cost overruns of £1.6m and first-half pre-tax profit of £1.5m. It posted a pre-tax profit of £3.4m for January-June a year ago.